is was the end of
his own dominions. He was now about to enter the territory of his foes.
With what fortune he did so must be left for later tales.

_HOW THE SPARTANS DIED AT THERMOPYLAE._

When Xerxes, as his father had done before him, sent to the Grecian
cities to demand earth and water in token of submission, no heralds were
sent to Athens or Sparta. These truculent cities had flung the heralds
of Darius into deep pits, bidding them to take earth and water from
there and carry it to the great king. This act called for revenge, and
whatever mercy he might show to the rest of Greece, Athens and Sparta
were doomed in his mind to be swept from the face of the earth. How they
escaped this dismal fate is what we have next to tell.

As one of the great men of Athens, Miltiades, had saved his native land
in the former Persian invasion, so a second patriotic citizen,
Themistocles, proved her savior in the dread peril which now threatened
her. But the work of Themistocles was not done in a single great battle,
as at Marathon, but in years of preparation. And a war between Athens
and the neighboring island of AEgina had much to do with this escape from
ruin.

To make war upon an island a land army was of no avail. A fleet was
necessary. The Athenians were accustomed to a commercial, though not to
a warlike, life upon the sea. Many of them were active, daring, and
skilful sailors, and when Themistocles urged that they should build a
powerful fleet he found approving listeners. Longer of sight than his
fellow-citizens, he warned them of the coming peril from Persia. The
conflict with the small island of AEgina was a small matter compared with
that threatened by the great kingdom of Persia. But to prepare against
one was to prepare against both. And Athens was just then rich. It
possessed valuable silver-mines at Laurium, in Attica, from which much
wealth came to the state. This money Themistocles urged the citizens to
use in building ships, and they were wise enough to take his advice, two
hundred ships of war being built. These ships, as it happened, were not
used for the purpose originally intended, that of the war with AEgina.
But they proved of inestimable service to Athens in the Persian war.

[Illustration: THE PLACE OF ASSEMBLY OF THE ATHENIANS.]

The vast preparations of Xerxes were not beheld without deep terror in
Greece. Spies were sent into Persia to discover what was being done.
They were captured and